1. Field of the Invention
The present invention relates to an ignition apparatus that supplies a high voltage to a spark plug of an internal combustion engine such as an automobile engine, etc., in order to generate a spark discharge, and also relates to a method for manufacturing a secondary coil thereof.
2. Description of the Related Art
Conventional internal combustion engine ignition apparatuses are configured such that a high-voltage tower that has a high-voltage terminal inside is made to project integrally from a side surface of a resin case, a primary coil and a secondary coil that includes a connecting member in which a winding finish end portion of a secondary wire is mounted to a base portion that is bent at a right angle and that extends alongside a side surface of the secondary coil are accommodated concentrically inside an insulated case, a tip end portion of the connecting member is electrically connected to the high-voltage terminal inside the high-voltage tower, and the primary coil and the secondary coil are fixed in an electrically-insulating resin layer that is formed by injecting and hardening an insulating resin inside the insulated case (see Patent Literature 1, for example).
Now, if the connecting member is placed alongside the side surface of the secondary bobbin, the secondary wire is obstructed by the connecting member and cannot be wound onto the secondary bobbin. Thus, the connecting member onto which a winding start end portion of the secondary wire is wound has been disposed on a flange portion at a first end of the secondary bobbin, and a tie portion onto which the winding finish end portion of the secondary wire is wound has been disposed on a flange portion at a second end of the secondary bobbin. That secondary bobbin is set in a winding machine, the winding start end portion of the secondary wire is wound onto the connecting member, the secondary wire is wound onto the secondary bobbin by the winding machine, the winding finish end portion thereof is wound onto the tie portion, and then the secondary coil is removed from the winding machine. The base portion that has been bent at a right angle such that the connecting member is placed alongside the side surface of the secondary bobbin is subsequently mounted to the flange portion at the second end of the secondary bobbin, and then the winding finish end portion of the secondary wire is removed from the tie portion and wound onto the base portion.
However, the rewinding operation in which the secondary wire that is wound onto the tie portion is removed and wound onto the base portion of the connecting member cannot be automated and has had to be performed manually, hindering productivity significantly.
In order to solve this problem, the base portion of the connecting member has been mounted to the flange portion at the second end of the secondary bobbin in such a way that an extending segment that is disposed so as to extend from the base portion is not placed alongside the side surface of the secondary bobbin. That secondary bobbin is set in a winding machine, the winding start end portion of the secondary wire is wound onto the connecting member, the secondary wire is wound onto the secondary bobbin by the winding machine, the winding finish end portion thereof is wound onto the base portion, and then the secondary coil is removed from the winding machine. The extending segment of the connecting member is subsequently bent at a right angle to the base portion so as to be placed alongside the side surface of the secondary bobbin.
Patent Literature 1: Japanese Patent Laid-Open No. 2002-291184 (Gazette)
In conventional internal combustion engine ignition apparatuses, because the extending segment of the connecting member is bent at a right angle to the base portion after the secondary wire has been wound onto the secondary bobbin, large bending forces have been required to plastically deform a bent portion between the base portion and the extending segment, etc. Thus, one disadvantage has been that misalignments of the connecting member relative to the secondary bobbin arise easily due to these bending forces, requiring correction of those misalignments.